Method and device for sequencing the zc sequences of the rach

ABSTRACT

A method and device for sequencing the ZC sequences of the RACH. According to the CM of OPSK, ZC sequences of the RACH are divided into low CM group and high CM group, to make the index of each ZC sequence within the low CM group smaller or larger than the index of each ZC sequence within the high CM group. The ZC sequences within the low CM group and within the high CM group are respectively divided into S sub-groups using S−1 maximum cyclic shift thresholds. The sequences are sequenced within each sub-group, to make the ZC sequences in adjacent sub-groups within the low CM group and within the high CM group have different sequencing and the ZC sequences in adjacent sub-groups between the low CM group and the high CM group have the same sequencing.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a National Stage application of PCT/CN2008/071830filed on Jul. 31, 2008, designating the United States and claimingpriority to Chinese Application No. 200710194922.0 filed on Dec. 5,2007.

FIELD OF THE INVENTION

The present invention relates to communication field, in particular to amethod and device for sequencing the ZC sequences of the random accesschannel.

BACKGROUND OF THE INVENTION

In the Long Term Evolution (LTE for short) system, cyclic shiftsequences of Zadoff-Chu (ZC for short) sequences are used as thepreamble by the Random Access Channel (RACH for short). These cyclicshift sequences are also referred to as Zero Correlation Zone (ZCZ forshort) sequences.

In practical systems, after a mobile phone is powered on, downlinksynchronization is first performed, and then the detection of theBroadcast Channel (BCH for short) is initiated. A base station informs,via the BCH channel, the mobile phone of the index and the step lengthof the cyclic shift of the first ZC sequence available for the RACH ofthe current cell. According to the index, the mobile phone makes use ofcertain mapping rule to calculate the serial number of the correspondingZC sequence, and then, generates usable ZCZ sequences according to thestep length of the cyclic shift and a certain “cyclic shift limitationrule” (the mobile phone is under a high speed circumstance).

If the number of the ZCZ sequences is smaller than a certain thresholdQ, the mobile phone automatically increments the sequence index, andcontinuously generates the ZCZ sequences using the next ZC sequence,until the total number of the ZCZ sequences is larger than or equal toQ. Finally, the mobile phone randomly selects one sequence from all thegenerated usable ZCZ sequences as a preamble to be sent.

In the high speed circumstance, the frequency offset caused by DopplerEffect will generate, during the process of the preamble detection, acorrelation peak alias, which will lead to a timing offset and a falsedetection. This problem is settled in the LTE system through limitingthe use of some cyclic shifts according to a certain rule, which is theabove mentioned “cyclic shift limitation rule”. Meanwhile, the cyclicshift limitation rule also limits the maximum cyclic shift N_(CS)corresponding to each ZC sequence, and this maximum cyclic shiftdirectly determines the maximum cell radius supported by each ZCsequence. Assuming that the distance between the correlation peak andthe correlation peak alias thereof is du, the relation between themaximum cyclic shift N_(CS) and du is:N _(CS)=min(du,N _(ZC)−2·du)  (1)

Wherein, N_(ZC) is the length of a ZC sequence, du can be calculated bythe following formula:

$\begin{matrix}{{du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}}\end{matrix} \right.} & (2)\end{matrix}$

Wherein, u is the serial number of the ZC sequence, and m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$a positive integer.

The mapping process between the indices and the serial numbers of the ZCsequences is actually the process of re-sequencing the ZC sequences.Wherein, the generation formula of the ZC sequences is shown as Equation(3) (0≦u≦NZC−1), and the serial number of the ZC sequence is the serialnumber used in the generation of each ZC sequence. The index of thesequence is the sequence number of each ZC sequence in a queue ofsequenced ZC sequences, where the ZC sequences are sequenced accordingto a certain criterion.

$\begin{matrix}{{{x_{u}(n)} = {\mathbb{e}}^{{- j}\;\frac{\;{\pi\;{{un}{({n + 1})}}}}{N_{ZC}}}},{0 \leq n \leq {N_{ZC} - 1}}} & (3)\end{matrix}$

At present, there are mainly two sequencing methods: one is to sequenceaccording to the cubic metric (CM for short, it is a standard formeasuring the Peak-to-Average Power Ratio of the emitted data, thelarger the CM is, the higher the Peak-to-Average Power Ratio is) of theZC sequences, and the other is to sequence according to the maximum cellradius supported by each ZC sequence under a high speed circumstance.

The first method is advantageous in that network planning of the ZCsequences can be conveniently performed according to the CM of a rootsequence so as to assign the sequences with smaller CMs to the cellswith larger radius, and the sequences with similar CMs to the same cell.Its shortcoming lies in that sequence fragments will be generated underthe high speed circumstance, which will cause the waste of thesequences. In other words, during the process of generating the ZCZsequences with the continuous incrementation of the sequence index, ifthe maximum cell radius supported by a ZC sequence is smaller than theradius of the current cell, this sequence neither could be used by thecurrent cell, nor it could be used by other cells having radiusessmaller than the maximum cell radius supported by this ZC sequence (thisis because that the index is continuously incremental, as shown in FIG.1).

The second method is advantageous in avoiding the generation of thesequence fragments, that is disadvantageous in that the CMs of the ZCsequences assigned to a cell differs greatly from each other so thatsequence planning can not be performed according to the CM.

A patent application of the present applicant with an application numberof 200710135732.1 provides a method and device for sequencing the ZCsequences of the random access channel, which can not only preventsequence fragments from being generated in the high speed circumstance,but also perform sequence planning and assigning according to the CMcharacter of the sequences. The method comprises the following steps:

step 1, the sequences are sequenced according to the CM values of thesequences;

step 2, the sequencing result of step 1 is grouped according to aparticular CM value (for example, the grouping may be performedaccording to the CM value of QPSK (about 1.2 dB));

step 3, the sequences in each group are sequenced, according to themaximum cell radius supported by the sequences under the high speedcircumstance, for a second time to obtain the final sequencing result.

The present invention modifies the sequencing method and device providedby the patent application with the application number of 200710135732.1.The present invention not only inherits all the advantages of theapplication, but also performs a better sequence planning and assigningaccording to the CM character of the sequence, so that sequences withsimilar CMs are assigned to the same cell.

SUMMARY OF THE INVENTION

In view of the above mentioned one or more problems, the presentinvention provides a method and a device for sequencing the ZC sequencesof the random access channel.

The present invention provides a method for sequencing the ZC sequencesof the random access channel. The method for sequencing the ZC sequencesof the random access channel according to the present inventioncomprises: step 1, according to Cubic Metric, CM, of Quadrature PhaseShift Keying, OPSK, ZC sequences of the RACH are divided into a low CMgroup and a high CM group, to make the index of each ZC sequence withinthe low CM group smaller or larger than the index of each ZC sequencewithin the high CM group; step 2, according to the maximum cell radiusor maximum cyclic shift supported by the ZC sequences under high speedcircumstance, the ZC sequences within the low CM group and within thehigh CM group are respectively divided into S sub-groups using S−1maximum cyclic shift thresholds, wherein S is a positive integer; andstep 3, according to the CMs of the ZC sequences, the sequences aresequenced within each sub-group, to make the ZC sequences in adjacentsub-groups within the low CM group and within the high CM group havedifferent sequencing and the ZC sequences in adjacent sub-groups betweenthe low CM group and the high CM group have the same sequencing, whereinthe last sub-group within the low CM group and the first sub-groupwithin the high CM group are adjacent with each other while the firstsub-group within the low CM group and the last sub-group within the highCM group are adjacent with each other.

The CMs of the ZC sequences within the low CM group are not larger thanthe CM of QPSK; and the CMs of the ZC sequences within the high CM groupare larger than the CM of QPSK.

In step 3, the sequences are sequenced from high to low or from low tohigh.

The index of the sequence within sub-group i is set smaller than theindex of the sequences within sub-group i+1, wherein 1≦i≦S−1, the i^(th)maximum cyclic shift threshold is Th_Ncs(i), and Th_Ncs(i)<Th_Ncs(i+1),wherein, 1≦i≦S−2 and i is a positive integer; as for the low CM group,when 1≦i≦S, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(i−1) andless than Th_Ncs(i); when i=1, the maximum value of the maximum cyclicshift supported by each ZC sequence within sub-group i is less thanTh_Ncs(1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not less thanTh_Ncs(S−1); or when 1≦i≦S, the maximum value of the maximum cyclicshift supported by each ZC sequence within sub-group i is larger thanTh_Ncs(i−1) and not larger than Th_Ncs(i); when i=1, the maximum valueof the maximum cyclic shift supported by each ZC sequence withinsub-group i is not larger than Th_Ncs(1); when i=S, the maximum value ofthe maximum cyclic shift supported by each ZC sequence within sub-groupis larger than Th_Ncs(S−1); and as for the high CM group, when 1≦i≦S,the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is not less than Th_Ncs(S−i) and less thanTh_Ncs(S−i+1); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not less thanTh_Ncs(S−1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group is less than Th_Ncs(1);or when 1≦i≦S, the maximum value of the maximum cyclic shift supportedby each ZC sequence within sub-group i is larger than Th_Ncs(S−i) andnot larger than Th_Ncs(S−i+1); when i=1, the maximum value of themaximum cyclic shift supported by each ZC sequence within sub-group i islarger than Th_Ncs(S−1); when i=S, the maximum value of the maximumcyclic shift supported by each ZC sequence within sub-group i is notlarger than Th_Ncs(1).

The index of the sequence within sub-group i is set smaller than theindex of the sequence within sub-group i+1, wherein 1≦i≦S−1, the i^(th)maximum cyclic shift threshold is Th_Ncs(i), and Th_Ncs(i)<Th_Ncs(i+1),wherein, 1≦i≦S−2 and i is a positive integer; as for the low CM group,when 1≦i≦S, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(i−1) andless than Th_Ncs(S−i+1); when i=1, the maximum value of the maximumcyclic shift supported by each ZC sequence within sub-group i is notless than Th_Ncs(S−i); when i=S, the maximum value of the maximum cyclicshift supported by each ZC sequence within sub-group i is less thanTh_Ncs(1); or when 1≦i≦S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−i) and not larger than Th_Ncs(S−i+1); when i=1, the maximumvalue of the maximum cyclic shift supported by each ZC sequence withinsub-group i is larger than Th_Ncs(S−1); when i=S, the maximum value ofthe maximum cyclic shift supported by each ZC sequence within sub-groupi is not larger than Th_Ncs(1); and as for the high CM group, when1≦i≦S, the maximum value of the maximum cyclic shift supported by eachZC sequence within sub-group i is not less than Th_Ncs(i−1) and lessthan Th_Ncs(i); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is less than Th_Ncs(1);when i=S, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(S−1); orwhen 1≦i≦S, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is larger than Th_Ncs(i−1) and notlarger than Th_Ncs(i); when i=1, the maximum value of the maximum cyclicshift supported by each ZC sequence within sub-group i is not largerthan Th_Ncs(1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group is larger thanTh_Ncs(S−1).

The maximum cyclic shift is Ar_(CS)=min(du,N_(ZC)−2·du), wherein, du isthe distance between the correlation peak alias and correlation peak,N_(ZC) is the length of the ZC sequence.

The distance between the correlation peak alias and correlation peak is,

${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N_{ZC}/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N_{ZC}/2} \right)}},}\end{matrix} \right.$wherein u is the serial number of the ZC sequence, m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$a positive integer.

The present invention also provides a method for sequencing the ZCsequences of the RACH, the method for sequencing the ZC sequences of theRACH according to the present invention comprises: setting the logicalindex of each ZC sequence as α, and the physical index of each ZCsequence as u, wherein 1≦u≦N−1, 0≦α≦N−2, N is the length of each ZCsequence and N=839; creating the physical indices u corresponding to thelogical indices α=0, 1, . . . , 837, the physical indices u are: 129,710, 140, 699, 120, 719, 210, 629, 168, 671, 84, 755, 105, 734, 93, 746,70, 769, 60, 779, 2, 837, 1, 838, 56, 783, 112, 727, 148, 691, 80, 759,42, 797, 40, 799, 35, 804, 73, 766, 146, 693, 31, 808, 28, 811, 30, 809,27, 812, 29, 810, 24, 815, 48, 791, 68, 771, 74, 765, 178, 661, 136,703, 86, 753, 78, 761, 43, 796, 39, 800, 20, 819, 21, 818, 95, 744, 202,637, 190, 649, 181, 658, 137, 702, 125, 714, 151, 688, 217, 622, 128,711, 142, 697, 122, 717, 203, 636, 118, 721, 110, 729, 89, 750, 103,736, 61, 778, 55, 784, 15, 824, 14, 825, 12, 827, 23, 816, 34, 805, 37,802, 46, 793, 207, 632, 179, 660, 145, 694, 130, 709, 223, 616, 228,611, 227, 612, 132, 707, 133, 706, 143, 696, 135, 704, 161, 678, 201,638, 173, 666, 106, 733, 83, 756, 91, 748, 66, 773, 53, 786, 10, 829, 9,830, 7, 832, 8, 831, 16, 823, 47, 792, 64, 775, 57, 782, 104, 735, 101,738, 108, 731, 208, 631, 184, 655, 197, 642, 191, 648, 121, 718, 141,698, 149, 690, 216, 623, 218, 621, 152, 687, 144, 695, 134, 705, 138,701, 199, 640, 162, 677, 176, 663, 119, 720, 158, 681, 164, 675, 174,665, 171, 668, 170, 669, 87, 752, 169, 670, 88, 751, 107, 732, 81, 758,82, 757, 100, 739, 98, 741, 71, 768, 59, 780, 65, 774, 50, 789, 49, 790,26, 813, 17, 822, 13, 826, 6, 833, 5, 834, 33, 806, 51, 788, 75, 764,99, 740, 96, 743, 97, 742, 166, 673, 172, 667, 175, 664, 187, 652, 163,676, 185, 654, 200, 639, 114, 725, 189, 650, 115, 724, 194, 645, 195,644, 192, 647, 182, 657, 157, 682, 156, 683, 211, 628, 154, 685, 123,716, 139, 700, 212, 627, 153, 686, 213, 626, 215, 624, 150, 689, 225,614, 224, 615, 221, 618, 220, 619, 127, 712, 147, 692, 124, 715, 193,646, 205, 634, 206, 633, 116, 723, 160, 679, 186, 653, 167, 672, 79,760, 85, 754, 77, 762, 92, 747, 58, 781, 62, 777, 69, 770, 54, 785, 36,803, 32, 807, 25, 814, 18, 821, 11, 828, 4, 835, 3, 836, 19, 820, 22,817, 41, 798, 38, 801, 44, 795, 52, 787, 45, 794, 63, 776, 67, 772, 72,767, 76, 763, 94, 745, 102, 737, 90, 749, 109, 730, 165, 674, 111, 728,209, 630, 204, 635, 117, 722, 188, 651, 159, 680, 198, 641, 113, 726,183, 656, 180, 659, 177, 662, 196, 643, 155, 684, 214, 625, 126, 713,131, 708, 219, 620, 222, 617, 226, 613, 230, 609, 232, 607, 262, 577,252, 587, 418, 421, 416, 423, 413, 426, 411, 428, 376, 463, 395, 444,283, 556, 285, 554, 379, 460, 390, 449, 363, 476, 384, 455, 388, 451,386, 453, 361, 478, 387, 452, 360, 479, 310, 529, 354, 485, 328, 511,315, 524, 337, 502, 349, 490, 335, 504, 324, 515, 323, 516, 320, 519,334, 505, 359, 480, 295, 544, 385, 454, 292, 547, 291, 548, 381, 458,399, 440, 380, 459, 397, 442, 369, 470, 377, 462, 410, 429, 407, 432,281, 558, 414, 425, 247, 592, 277, 562, 271, 568, 272, 567, 264, 575,259, 580, 237, 602, 239, 600, 244, 595, 243, 596, 275, 564, 278, 561,250, 589, 246, 593, 417, 422, 248, 591, 394, 445, 393, 446, 370, 469,365, 474, 300, 539, 299, 540, 364, 475, 362, 477, 298, 541, 312, 527,313, 526, 314, 525, 353, 486, 352, 487, 343, 496, 327, 512, 350, 489,326, 513, 319, 520, 332, 507, 333, 506, 348, 491, 347, 492, 322, 517,330, 509, 338, 501, 341, 498, 340, 499, 342, 497, 301, 538, 366, 473,401, 438, 371, 468, 408, 431, 375, 464, 249, 590, 269, 570, 238, 601,234, 605, 257, 582, 273, 566, 255, 584, 254, 585, 245, 594, 251, 588,412, 427, 372, 467, 282, 557, 403, 436, 396, 443, 392, 447, 391, 448,382, 457, 389, 450, 294, 545, 297, 542, 311, 528, 344, 495, 345, 494,318, 521, 331, 508, 325, 514, 321, 518, 346, 493, 339, 500, 351, 488,306, 533, 289, 550, 400, 439, 378, 461, 374, 465, 415, 424, 270, 569,241, 598, 231, 608, 260, 579, 268, 571, 276, 563, 409, 430, 398, 441,290, 549, 304, 535, 308, 531, 358, 481, 316, 523, 293, 546, 288, 551,284, 555, 368, 471, 253, 586, 256, 583, 263, 576, 242, 597, 274, 565,402, 437, 383, 456, 357, 482, 329, 510, 317, 522, 307, 532, 286, 553,287, 552, 266, 573, 261, 578, 236, 603, 303, 536, 356, 483, 355, 484,405, 434, 404, 435, 406, 433, 235, 604, 267, 572, 302, 537, 367, 472,296, 543, 336, 503, 305, 534, 373, 466, 280, 559, 279, 560, 419, 420,240, 599, 258, 581, 229, 610; sequencing the ZC sequences of the RACHaccording to the created mapping relationship between the logicalindices and the physical indices.

The present invention also provides a device for sequencing the ZCsequences of the RACH, the device for sequencing the ZC sequences of theRACH according to the present invention comprises, a first groupdividing unit configured to divide ZC sequences of the RACH into a lowCM group and a high CM group according to the CM of QPSK, to make theindex of each ZC sequence within the low CM group smaller or larger thanthe index of each ZC sequence within the high CM group; a second groupdividing unit configured to respectively divide the ZC sequences withinthe low CM group and within the high CM group into S sub-groups usingS−1 maximum cyclic shift thresholds according to the maximum cell radiusor maximum cyclic shift supported by the ZC sequences under high speedcircumstance, wherein S is a positive integer; and a sequencing unitconfigured to sequence the sequences within each sub-group according tothe CMs of the ZC sequences, to make the ZC sequences in adjacentsub-groups within the low CM group and within the high CM group havedifferent sequencing, and the ZC sequences in adjacent sub-groupsbetween the low CM group and the high CM group have the same sequencing,wherein the last sub-group within the low CM group and the firstsub-group within the high CM group are adjacent with each other whilethe first sub-group within the low CM group and the last sub-groupwithin the high CM group are adjacent with each other.

The method and device for sequencing the ZC sequences of the RACHprovided by the present invention not only enables the assignment of thesequences according to the CMs, but also enables the collection of thesequence fragments for use, so that the generation of sequence fragmentscan be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrated here provide a further understanding of thepresent invention and form a part of the present application. Theexemplary embodiments and the description thereof are used to explainthe present invention without unduly limiting the scope of the presentinvention, wherein:

FIG. 1 is a schematic diagram of the generation of the sequencefragments in the prior art;

FIG. 2 is a flowchart of the method for sequencing the ZC sequences ofthe random access channel according to an embodiment of the presentinvention;

FIG. 3 is a schematic diagram showing the grouping of the ZC sequencesof the RACH according to an embodiment of the present invention;

FIG. 4 a-4 d are schematic diagrams showing the grouping and sequencingof the ZC sequences of the RACH according to an embodiment of thepresent invention; and

FIG. 5 is a schematic diagram showing the corresponding relation betweenthe physical indices and the CM values of the ZC sequences according toan embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments of the present invention will be described hereinafterin detail in conjunction with the drawings thereof.

The present invention provides a method for sequencing the ZC sequencesof the RACH.

FIG. 2 shows the method for sequencing the ZC sequences of the RACHaccording to an embodiment of the present invention. As shown in FIG. 2,the method comprises:

step S202, according to the CM of OPSK, ZC sequences of the RACH aredivided into low CM group and high CM group, to make the index of eachZC sequence within the low CM group smaller or larger than the index ofeach ZC sequence within the high CM group.

step S204, according to the maximum cell radius or maximum cyclic shiftsupported by the ZC sequences under a high speed circumstance, the ZCsequences within the low CM group and within the high CM group arerespectively divided into S sub-groups using S−1 maximum cyclic shiftthresholds, wherein S is a positive integer.

step S206, according to the CMs of the ZC sequences, the sequences aresequenced within each sub-group, to make the ZC sequences in adjacentsub-groups within the low CM group and within the high CM group havedifferent sequencing and the ZC sequences in adjacent sub-groups betweenthe low CM group and the high CM group have the same sequencing, whereinthe last sub-group within the low CM group and the first sub-groupwithin the high CM group are adjacent with each other while the firstsub-group within the low CM group and the last sub-group within the highCM group are adjacent with each other.

In the FDD mode of the LTE, the length of the ZC sequences used by theRACH is 839, and the number of usable sequences is 838.

All the ZC sequences of the RACH are divided, using the CM of QPSK as athreshold, into two groups, i.e., the low CM group and the high CMgroup. The CMs of the ZC sequences in the low CM group are smaller thanor equal to the CM of QPSK, while the CMs of the ZC sequences in thehigh CM group are larger than the CM of QPSK, which is 1.2 dB.

After the final sequencing process, the indices of the sequences in thelow CM group are smaller than the indices of the sequences in the highCM group, as shown in FIG. 3, or the indices of the sequences in the lowCM group are larger than the indices of the sequences in the high CMgroup.

According to the maximum cell radius or maximum cyclic shift supportedby the ZC sequences under a high speed circumstance, the ZC sequenceswithin each group are divided into S sub-groups using S−1 maximum cyclicshift thresholds, these sub-groups are numbered with 1 to S, wherein Sis a positive integer.

After the final sequencing process is completed, the indices of thesequences in sub-group i are all smaller than the indices of thesequences in sub-group i+1, 1≦i≦S−1, the i^(th) maximum cyclic shiftthreshold is Th_Ncs(i), and Th_Ncs(i)<Th_Ncs(i+1), wherein, 1≦i≦S−2 andi is a positive integer.

Setting S=16, then 15 maximum cyclic shift thresholds Th_Ncs(1),Th_Ncs(2), . . . , Th_Ncs(15) are 15, 18, 22, 26, 32, 38, 46, 55, 68,82, 100, 128, 158, 202, 237, respectively.

If the maximum value of the maximum cyclic shift supported by the ZCsequences in the j^(th) sub-group under the high speed circumstance ismade to be MaxNcs(i), 1≦i≦S, then each sub-group in each group shallsatisfy the following property (Property a), as shown in FIG. 4 a: forthe low CM group, when 1≦i≦S, Th_Ncs(i−1)≦MaxNcs(i)<Th_Ncs(i), when i=1,MaxNcs(1)<Th_Ncs(1), when i=S, Th_Ncs(S−1)≦MaxNcs(S); for the high CMgroup, when 1≦i≦S, Th_Ncs(S−i)≦MaxNcs(i)<Th_Ncs(S−i+1), when i=1,Th_Ncs(S−1)≦MaxNcs(1), when i=S, MaxNcs(S)<Th_Ncs(1);

or the following property (Property b) shall be satisfied, as shown inFIG. 4 b: for the low CM group, when 1≦i≦S,Th_Ncs(i−1)<MaxNcs(i)≦Th_Ncs(i), when i=1, MaxNcs(1)≦Th_Ncs(1), wheni=S, Th_Ncs(S−1)<MaxNcs(S); for the high CM group, when 1<i<S,Th_Ncs(S−i)<MaxNcs(i)≦Th_Ncs(S−i+1), when i=1, Th_Ncs(S−1)<MaxNcs(1),when i=S, MaxNcs(S)≦Th_Ncs(1).

The following method can be used to realize the sequencing target instep S204.

step S2042, for the two groups of sequences obtained in step S202, i.e.,the low CM group and the high CM group, the ZC sequences in each groupare sequenced according to the maximum cell radius or the maximum cyclicshift supported by the ZC sequences under the high speed circumstance.The principles for the sequencing may be: the low CM group is sequencedin the increasing order, while the high CM group is sequenced in thedecreasing order, the two groups use different sequencing principles.

step S2044, in each group, the sequencing result obtained in step S2042is divided, according to S−1 maximum cyclic shift thresholds, intoseveral segments, each of which is taken as a sub-group.

In each sub-group of each group, the sequencing is performed accordingto the CMs of the ZC sequences. In the low CM group, the sub-group withan odd sequence number is sequenced in the decreasing order, while thesub-group with an even sequence number is sequenced in the increasingorder; in the high CM group, the sub-group with an odd sequence numberis sequenced in the increasing order, while the sub-group with an evensequence number is sequenced in the decreasing order. Thus it is ensuredthat the sub-groups at the boundary of the two groups have the samesequencing order (the boundary of the groups shall be considered in acyclic view). The sequencing results are shown in FIG. 4 c and FIG. 4 d,the indices are from 1 to N (N is the total number of the ZC sequences).In addition, the indices of the sequences are cyclic, that is, the indexof the sequence which is next to the sequence with an index of N is 1.

The above mentioned maximum cyclic shift of the ZC sequence isN_(CS)=min(du,N_(ZC)−2·du), wherein, du is the distance between thecorrelation peak alias and the correlation peak, N_(ZC) is the length ofthe ZC sequence, and the distance between the correlation peak alias andthe correlation peak is

${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$wherein u is the serial number of the ZC sequence, m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$a positive integer.

The most essential feature of the aforementioned sequencing result liein that the sequences are divided into two groups according to the CM ofQPSK; the sequences in each group are further divided into sub-groupsaccording to the maximum cyclic shift thresholds; and the sequences ineach sub-group are further sequenced according to the CM of the ZCsequences.

The sequencing results obtained from the above processes are shown inTable 1 to Table 4, wherein Table 1 and Table 2 show the elements of thelow CM group and the high CM group, and Table 3 and Table 4 show theelements of each sub-group (SG) in the low CM group and the high CMgroup when Property a is satisfied.

TABLE 1 Low CM group 838  21 798  63 745  83 171 655 202 643 701 689  1818  41 776  94 756 668 184 637 196 138 150 837  20  38  56 734 106 165207 677 658 705 709  2 819 801 783 105 733 674 632 162 181 134 130  3816  37 770 766 671 172 118 646 661 125 148 836  23 802  69  73 168 667721 193 178 714 691  4 817 800  60 747  85 728 206 194 718 695 149 835 22  39 779  92 754 111 633 645 121 144 690  5  24  43 769 103 753 174204 636 156 142 710 834 815 796  70 736  86 665 635 203 683 697 129 833 26 790 772  74  97 653 117 199 717 696 623  6 813  49  67 765 742 186722 640 122 143 216 832 814  44 773 744 750 110 651 656 211 693 708  7 25 795  66  95  89 729 188 183 628 146 131 831 810  50 771 737  81 675638 210 154 213 622  8  29 789  68 102 758 164 201 629 685 626 217 830 27  52 780 101 732 664 680 197 715 703 218  9 812 787  59 738 107 175159 642 124 136 621 829 809 788 778  91  88 652 634 195 716 133 219  10 30  51  61 748 751 187 205 644 123 706 620  11  28 793 777 740 759 173158 120 699 152 619 828 811  46  62  99  80 666 681 719 140 687 220  12 31 791  57  90  79 676 720 659 155 151 223 827 808  48 782 749 760 163119 180 684 688 616  13  34 792  58 762 672 209 663 647 694 625 221 826805  47 781  77 167 630 176 192 145 214 618  14  35 786  71 741 169 160114 649 135 126 617 825 804  53 768  98 670 679 725 190 704 713 222  15806  45  93 755 752 112 678 177 702 711 224 824  33 794 746  84  87 727161 662 137 128 615 823  32  64  72 743 108 116 189 660 700 692 613  16807 775 767  96 731 723 650 179 139 147 226  17 799 774 764 739 669 185198 648 212 707 612 822  40  65  75 100 170 654 641 191 627 132 227 820 36 785 735 757 166 631 113 182 686 215 614  19 803  54 104  82 673 208726 657 153 624 225  18 797  55  76  78 109 639 724 682 141 712 611 821 42 784 763 761 730 200 115 157 698 127 228

TABLE 2 High CM group 229 258 574 421 558 437 398 292 362 531 344 346321 610 576 265 589 281 371 441 289 477 309 495 501 518 609 263 275 250374 468 367 550 455 530 488 338 515 230 257 564 588 465 404 472 457 384480 351 331 324 608 582 572 251 463 435 459 382 451 359 342 508 519 231599 267 590 376 396 380 383 388 358 497 522 320 603 240 563 249 430 443400 456 541 481 511 317 517 236 570 276 246 409 369 439 303 298 529 328319 322 232 269 271 593 432 470 287 536 386 310 512 520 516 607 256 568417 407 445 552 449 453 482 327 332 323 604 583 584 422 467 394 286 390478 357 345 507 235 268 255 416 372 368 553 365 361 527 494 337 606 571277 423 410 471 440 474 452 312 510 502 233 241 562 559 429 378 399 535387 355 329 506 234 598 561 280 557 461 379 304 385 484 524 333 605 575278 248 282 397 460 363 454 528 315 491 237 264 420 591 377 442 458 476294 311 350 348 602 270 419 424 462 393 381 300 545 485 489 349 601 569266 415 436 446 551 539 360 354 340 490 238 567 573 247 403 405 288 293479 356 499 514 577 272 586 592 375 434 548 546 542 483 341 325 262 242253 373 464 555 291 538 297 313 498 492 261 597 279 466 406 284 448 301295 526 318 347 578 274 560 426 433 370 391 305 544 525 521 330 600 565254 413 444 469 549 534 296 314 316 509 239 244 585 414 395 438 290 299543 353 523 505 260 595 587 425 431 401 302 540 533 486 339 334 579 566252 412 408 447 537 389 306 487 500 336 259 273 245 427 283 392 473 450532 352 326 503 580 243 594 428 556 285 366 475 307 343 513 504 581 596418 411 402 554 547 364 308 496 493 335

TABLE 3 Low CM group (Property a) SG SG SG SG SG SG SG SG SG SG SG SG SGSG SG SG 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 129  56  80  35 808  24 86 744 217  12 228 832 687   5 225   3 710 783 759 804  31 815 753  95622 827 611   7 152 834 614 836 140 112  42 766 811 791 761 202 128 816227 831 144 806 615 820 699 727 797  73  28  48  78 637 711  23 612   8695  33 224  19 719 148  40 693  30 771 796 649 697  34 132 823 134 788618 817 120 691 799 146 809  68  43 190 142 805 707  16 705  51 221  22629 812  74  39 658 122  37 706 792 138 764 220 798 210  27 765 800 181717 802 133  47 701  75 619  41 168  29 661 819 702 203 793 143  64 640740 127  38 671 810 178  20 137 636  46 696 775 199  99 712 801  84 703818 125 721 207 704  57 162 743 147  44 755 136  21 714 118 632 135 782677  96 692 795 105 151 729 660 161 735 176  97 124  52 734 688 110 179678 104 663 742 715 787 746  89 694 201 101 119 166 193  45  93 750 145638 738 720 673 646 794  70 736 709 666 108 681 172 205  63 769 103 130173 731 158 667 634 776 779  61 223 733 631 164 664 633 772  60 778 616106 208 675 175 206  67   2 784 756 655 665 652 723  72 837  55  83 184174 187 116 767   1 824 748 197 668 676 679  76 838  15  91 642 171 163160 763 825  66 648 170 185 186 745  14 773 191 669 654 653  94  53 718 87 639 167 737 786 121 752 200 672 102  10 141 670 114 760  90 829 698169 725  79 749   9 149 751 189 754 109 830 690  88 650  85 730 623 107724  77 165 216 732 115 762 674 218 758 194  92 728 621  81 645 747 111 82 195 781 209 757 644  58 630 100 647  62 204 739 192 777 635  98 182 69 117 741 657 770 722 768 682  54 651  71 157 785 188  59 156 803 680780 683  36 159  65 211 807 198 774 628  32 641 789 154  25 113  50 685814 726  49 716 821 656 790 123  18 183 813 700 828 659  26 139  11 180822 212 835 177  17 627   4 662 826 686 643  13 153 196   6 213 155 833626 684 215 625 624 214 689 126 150 713 708 131 219 620 617 222 613 226

TABLE 4 High CM group (Property a) SG SG SG SG SG SG SG SG SG SG SG SGSG SG SG SG 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 609 323 237 509 257346 608 546 242 317 603 484 604 530 367 503 230 516 602 330 582 493 231293 597 522 236 355 235 309 472 336 232 320 600 338 566 500 260 288 274307 303 434 572 265 296 534 607 519 239 501 273 339 579 551 565 532 536405 267 574 543 305 577 334 244 498 584 351 268 284 402 553 356 435 302233 466 262 505 595 341 255 488 571 555 437 286 483 404 537 606 373 587359 243 499 254 306 563 471 383 552 433 280 252 480 596 340 585 533 276368 456 287 406 559 418 544 275 497 245 550 430 253 482 573 560 421 295564 342 594 289 409 586 357 266 279 416 454 561 301 588 439 398 583 510578 419 423 385 278 538 251 400 441 256 329 261 420 426 292 589 366 412461 549 263 240 413 547 250 473 427 378 290 576 599 428 291 246 401 467465 535 258 411 548 593 438 372 374 304 581 463 381 417 468 557 415 308610 376 458 422 371 282 424 531 229 444 399 248 408 436 569 358 395 440591 431 403 270 481 283 380 445 464 396 598 316 556 459 394 375 443 241523 285 442 393 249 447 554 397 446 590 392 379 470 370 269 448 460 369469 570 391 449 462 365 238 457 390 377 474 601 382 363 429 300 605 389476 410 539 234 450 455 407 299 294 384 432 540 545 451 281 475 542 388558 364 297 386 425 362 528 453 414 477 311 478 592 541 344 361 247 298495 452 562 527 345 387 277 312 494 360 568 313 318 479 271 526 521 529272 525 331 310 567 314 508 485 264 353 514 354 575 486 325 511 580 487321 328 259 352 518 524 343 315 496 337 512 502 327 349 350 490 489 504326 335 513 515 319 324 520 332 507 506 333 491 348 492 347 517 322

The present invention further provides a method for sequencing the ZCsequences of the RACH.

For the ZC sequences generated according to Equation 3, the sequencewith a physical index u and the sequence with a physical index N-u havethe same CM value, as shown in FIG. 5, which is a schematic diagramshowing the corresponding relation between the physical indices and theCM values of the ZC sequences according to an embodiment of the presentinvention. According to the method for sequencing the ZC sequences ofthe above embodiments, the sequencing is performed (from high to low orfrom low to high) according to the CM values of the sequences in eachsub-group, thus in each sub-group, sequence u and N-u (u is the physicalindex of the sequence, and 0<=u<=N−1, N is the length of each ZCsequence) are exchangeable in order. At last, the mapping relationshipbetween logical indices and physical indices shown in Table 5 can beobtained by combining Table 3 and Table 4.

TABLE 5 Sub-group group (logical indices) Physical indices low CM SG1(0-23) 129, 710, 140, 699, 120, 719, 210, 629, 168, 671, 84, 755, 105,734, 93, group 746, 70, 769, 60, 779, 2, 837, 1, 838 SG2 (24-29) 56,783, 112, 727, 148, 691 SG3 (30-35) 80, 759, 42, 797, 40, 799 SG4(36-41) 35, 804, 73, 766, 146, 693 SG5 (42-51) 31, 808, 28, 811, 30,809, 27, 812, 29, 810 SG6 (52-63) 24, 815, 48, 791, 68, 771, 74, 765,178, 661, 136, 703 SG7 (64-75) 86, 753, 78, 761, 43, 796, 39, 800, 20,819, 21, 818 SG8 (76-89) 95, 744, 202, 637, 190, 649, 181, 658, 137,702, 125, 714, 151, 688 SG9 (90-115) 217, 622, 128, 711, 142, 697, 122,717, 203, 636, 118, 721, 110, 729, 89, 750, 103, 736, 61, 778, 55, 784,15, 824, 14, 825 SG10 (116-135) 12, 827, 23, 816, 34, 805, 37, 802, 46,793, 207, 632, 179, 660, 145, 694, 130, 709, 223, 616 SG11 (136-167)228, 611, 227, 612, 132, 707, 133, 706, 143, 696, 135, 704, 161, 678,201, 638, 173, 666, 106, 733, 83, 756, 91, 748, 66, 773, 53, 786, 10,829, 9, 830 SG12 (168-203) 7, 832, 8, 831, 16, 823, 47, 792, 64, 775,57, 782, 104, 735, 101, 738, 108, 731, 208, 631, 184, 655, 197, 642,191, 648, 121, 718, 141, 698, 149, 690, 216, 623, 218, 621 SG13(204-263) 152, 687, 144, 695, 134, 705, 138, 701, 199, 640, 162, 677,176, 663, 119, 720, 158, 681, 164, 675, 174, 665, 171, 668, 170, 669,87, 752, 169, 670, 88, 751, 107, 732, 81, 758, 82, 757, 100, 739, 98,741, 71, 768, 59, 780, 65, 774, 50, 789, 49, 790, 26, 813, 17, 822, 13,826, 6, 833 SG14 (264-327) 5, 834, 33, 806, 51, 788, 75, 764, 99, 740,96, 743, 97, 742, 166, 673, 172, 667, 175, 664, 187, 652, 163, 676, 185,654, 200, 639, 114, 725, 189, 650, 115, 724, 194, 645, 195, 644, 192,647, 182, 657, 157, 682, 156, 683, 211, 628, 154, 685, 123, 716, 139,700, 212, 627, 153, 686, 213, 626, 215, 624, 150, 689 SG15 (328-383)225, 614, 224, 615, 221, 618, 220, 619, 127, 712, 147, 692, 124, 715,193, 646, 205, 634, 206, 633, 116, 723, 160, 679, 186, 653, 167, 672,79, 760, 85, 754, 77, 762, 92, 747, 58, 781, 62, 777, 69, 770, 54, 785,36, 803, 32, 807, 25, 814, 18, 821, 11, 828, 4, 835 SG16 (384-455) 3,836, 19, 820, 22, 817, 41, 798, 38, 801, 44, 795, 52, 787, 45, 794, 63,776, 67, 772, 72 767, 76, 763, 94, 745, 102, 737, 90, 749, 109, 730,165, 674, 111, 728, 209, 630, 204, 635, 117, 722, 188, 651, 159, 680,198, 641, 113, 726, 183, 656, 180, 659, 177, 662, 196, 643, 155, 684,214, 625, 126, 713, 131, 708, 219, 620, 222, 617, 226, 613 High CM SG1(456-513) 230, 609, 232, 607, 262, 577, 252, 587, 418, 421, 416, 423,413, 426, 411, group 428, 376, 463, 395, 444, 283, 556, 285, 554, 379,460, 390, 449, 363, 476, 384, 455, 388, 451, 386, 453, 361, 478, 387,452, 360, 479, 310, 529, 354, 485, 328, 511, 315, 524, 337, 502, 349,490, 335, 504, 324, 515 SG2 (514-561) 323, 516, 320, 519, 334, 505, 359,480, 295, 544, 385, 454, 292, 547, 291, 548, 381, 458, 399, 440, 380,459, 397, 442, 369, 470, 377, 462, 410, 429, 407, 432, 281, 558, 414,425, 247, 592, 277, 562, 271, 568, 272, 567, 264, 575, 259, 580 SG3(562-629) 237, 602, 239, 600, 244, 595, 243, 596, 275, 564, 278, 561,250, 589, 246, 593, 417, 422, 248, 591, 394, 445, 393, 446, 370, 469,365, 474, 300, 539, 299, 540, 364, 475, 362, 477, 298, 541, 312, 527,313, 526, 314, 525, 353, 486, 352, 487, 343, 496, 327, 512, 350, 489,326, 513, 319, 520, 332, 507, 333, 506, 348, 491, 347, 492, 322, 517 SG4(630-659) 330, 509, 338, 501, 341, 498, 340, 499, 342, 497, 301, 538,366, 473, 401, 438, 371, 468, 408, 431, 375, 464, 249, 590, 269, 570,238, 601, 234, 605 SG5 (660-707) 257, 582, 273, 566, 255, 584, 254, 585,245, 594, 251, 588, 412, 427, 372, 467, 282, 557, 403, 436, 396, 443,392, 447, 391, 448, 382, 457, 389, 450, 294, 545, 297, 542, 311, 528,344, 495, 345, 494, 318, 521, 331, 508, 325, 514, 321, 518 SG6 (708-729)346, 493, 339, 500, 351, 488, 306, 533, 289, 550, 400, 439, 378, 461,374, 465, 415, 424, 270, 569, 241, 598 SG7 (730-751) 231, 608, 260, 579,268, 571, 276, 563, 409, 430, 398, 441, 290, 549, 304, 535, 308, 531,358, 481, 316, 523 SG8 (752-765) 293, 546, 288, 551, 284, 555, 368, 471,253, 586, 256, 583, 263, 576 SG9 (766-777) 242, 597, 274, 565, 402, 437,383, 456, 357, 482, 329, 510 SG10 (778-789) 317, 522, 307, 532, 286,553, 287, 552, 266, 573, 261, 578 SG11 (790-795) 236, 603, 303, 536,356, 483 SG12 (796-803) 355, 484, 405, 434, 404, 435, 406, 433 SG13(804-809) 235, 604, 267, 572, 302, 537 SG14 (810-815) 309, 530, 265,574, 233, 606 SG15 (816-819) 367, 472, 296, 543 SG16 (820-837) 336, 503,305, 534, 373, 466, 280, 559, 279, 560, 419, 420, 240, 599, 258, 581,229, 610

In a practical system, according to the random access system parameters(comprising the logical index of the first usable ZC sequence, cyclicshift, and high speed indication, etc.), a base station and a mobileterminal use the following method, to generate a random access preamblesequence of the current cell (the base station transmits the systemparameters to the mobile terminal via broadcast channel).

1. the logical index x of the first usable ZC sequence is obtained;

2. the physical index of the ZC sequence is determined according toTable 5 and x;

3. a physical root sequence is generated using the determined physicalindex according to Equation 3;

4. the preamble sequence of the RACH is generated according to thecyclic shift Ncs and cyclic shift limitation rule;

5. if the total number of the current preamble sequences is less than anupper limit Q (Q=64), the logical index x of the usable ZC sequences isincremented, and steps 2-5 are repeated until the total number of thepreamble sequences reaches to Q.

The present invention further provides a device for sequencing the ZCsequences of the RACH, which comprises: a first group dividing unitconfigured to divide the ZC sequences of the RACH into a low CM groupand a high CM group according to the CM of QPSK, to make the index ofeach ZC sequence within the low CM group smaller or larger than theindex of each ZC sequence within the high CM group; a second groupdividing unit configured to respectively divide the ZC sequences withinthe low CM group and within the high CM group into S sub-groups usingS−1 maximum cyclic shift thresholds according to the maximum cell radiusor maximum cyclic shift supported by the ZC sequences under the highspeed circumstance, wherein S is a positive integer; and a sequencingunit configured to sequence the sequences within each sub-groupaccording to the CMs of the ZC sequences, to make the ZC sequences inadjacent sub-groups within the low CM group and within the high CM grouphave different sequencing, and the ZC sequences in adjacent sub-groupsbetween the low CM group and the high CM group have the same sequencing,wherein the last sub-group within the low CM group and the firstsub-group within the high CM group are adjacent with each other whilethe first sub-group within the low CM group and the last sub-groupwithin the high CM group are adjacent with each other.

The present invention not only enables the assignment of the sequencesaccording to the CMs, but also enables the collection of the sequencefragments for use, so that the generation of sequence fragments can beavoided. Meanwhile, the present invention is fully compatible to thefirst and the second re-sequencing methods described in the Backgroundof the Invention, without introducing any extra signaling cost.

The descriptions above are only preferable embodiments of the presentinvention, which are not used to restrict the present invention. Forthose skilled in the art, the present invention may have various changesand variations. Any amendments, equivalent substitutions, improvementsetc. within the spirit and principle of the present invention are allincluded in the scope of the claims of the present invention.

The invention claimed is:
 1. A method for sequencing the Zadoff-Chu, ZC,sequences of the Random Access Channel, RACH, comprising the followingsteps, step 1, according to Cubic Metric, CM, of Quadrature Phase ShiftKeying, QPSK, ZC sequences of the RACH are divided into a low CM groupand a high CM group, to make a logical index of each ZC sequence withinthe low CM group smaller or larger than a logical index of each ZCsequence within the high CM group; step 2, according to a maximum cellradius or maximum cyclic shift supported by the ZC sequences under highspeed circumstance, the ZC sequences within the low CM group and withinthe high CM group are respectively divided into S sub-groups using S−1maximum cyclic shift thresholds, wherein S is a positive integer; andstep 3, according to the CMs of the ZC sequences, the sequences aresequenced within each sub-group, to make the ZC sequences in adjacentsub-groups within the low CM group and within the high CM group havedifferent sequencing and the ZC sequences in adjacent sub-groups betweenthe low CM group and the high CM group have the same sequencing, whereinthe last sub-group within the low CM group and the first sub-groupwithin the high CM group are adjacent with each other while the firstsub-group within the low CM group and the last sub-group within the highCM group are adjacent with each other; wherein the CMs of the ZCsequences within the low CM group are not larger than the CM of OPSK;and the CMs of the ZC sequences within the high CM group are larger thanthe CM of OPSK; wherein the sequences are sequenced from high to low orfrom low to high; wherein the logical index of the sequence withinsub-group i is set smaller than the logical index of the sequenceswithin sub-group i+1, wherein 1≦i≦S−1, the i^(th) maximum cyclic shiftthreshold is Th_Ncs(i), and Th_Ncs(i)<Th_Ncs(i+1), wherein, 1≦i≦S−2 andi is a positive integer; as for the low CM group, when 1<i<S, themaximum value of the maximum cyclic shift supported by each ZC sequencewithin sub-group i is not less than Th_Ncs(i−1) and less than Th_Ncs(i);when i=1, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is less than Th_Ncs(1); when i=S,the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is not less than Th_Ncs(S−1); or when 1<i<S,the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is larger than Th_Ncs(i−1) and not largerthan Th_Ncs(i); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not larger thanTh_Ncs(1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−1); and as for the high CM group, when 1<i<S, the maximum valueof the maximum cyclic shift supported by each ZC sequence withinsub-group i is not less than Th_Ncs(S−i) and less than Th_Ncs(S−i+1);when i=1, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(S−1); wheni=S, the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is less than Th_Ncs(1); or when 1<i<S, themaximum value of the maximum cyclic shift supported by each ZC sequencewithin sub-group i is larger than Th_Ncs(S−i) and not larger thanTh_Ncs(S−i+1); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not larger thanTh_Ncs(1); or, wherein the logical index of the sequence withinsub-group i is set smaller than the logical index of the sequence withinsub-group i+1, wherein 1≦i≦S−1, the ith maximum cyclic shift thresholdis Th_Ncs(i), and Th_Ncs(i)<Th_Ncs(i+1), wherein, 1≦i≦S−2 and i is apositive integer; as for the low CM group, when 1<i<S, the maximum valueof the maximum cyclic shift supported by each ZC sequence withinsub-group i is not less than Th_Ncs(i−1) and less than Th_Ncs(S−i+1);when i=1, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(S−i); wheni=S, the maximum value of the maximum cyclic shift supported b each ZCsequence within sub-group i is less than Th_Ncs(1); or when 1<i<S, themaximum value of the maximum cyclic shift supported by each ZC sequencewithin sub-group i is larger than Th_Ncs(S−i) and not larger thanTh_Ncs(S−i+1); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not larger thanTh_Ncs(1); and as for the high CM group, when 1<i<S, the maximum valueof the maximum cyclic shift supported by each ZC sequence withinsub-group i is not less than Th_Ncs(i−1) and less than Th_Ncs(i); wheni=1, the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is less than Th_Ncs(1); when i=S, themaximum value of the maximum cyclic shift supported by each ZC sequencewithin sub-group i is not less than Th_Ncs(S−1); or when 1<i<S, themaximum value of the maximum cyclic shift supported by each ZC sequencewithin sub-group i is larger than Th_Ncs(i−1) and not larger thanTh_Ncs(i); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not larger thanTh_Ncs(1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−1).
 2. The method according to claim 1, wherein the maximumcyclic shift is N_(CS)=min(du,N_(ZC)−2·du), wherein, du is the distancebetween the correlation peak alias and correlation peak, N_(ZC) is thelength of the ZC sequence.
 3. The method according to claim 2, whereinthe distance between the correlation peak alias and correlation peak is,${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N_{ZC}/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N_{ZC}/2} \right)}},}\end{matrix} \right.$ wherein u is the physical index of the ZCsequence, m is the minimum positive integer which makes$\frac{{m \cdot N_{ZC}} - 1}{u}$ a positive integer.
 4. A device forsequencing the ZC sequences of the RACH, comprising: a first groupdividing unit connected with a second group dividing unit and configuredto divide ZC sequences of the RACH into a low CM group and a high CMgroup according to the CM of QPSK, to make a logical index of each ZCsequence within the low CM group smaller or larger than a logical indexof each ZC sequence within the high CM group; the second group dividingunit connected with the first group dividing unit and configured torespectively divide the ZC sequences within the low CM group and withinthe high CM group into S sub-groups using S−1 maximum cyclic shiftthresholds according to a maximum cell radius or maximum cyclic shiftsupported by the ZC sequences under high speed circumstance, wherein Sis a positive integer; and a sequencing unit connected with the secondgroup dividing unit and configured to sequence the sequences within eachsub-group according to the CMs of the ZC sequences, to make the ZCsequences in adjacent sub-groups within the low CM group and within thehigh CM group have different sequencing, and the ZC sequences inadjacent sub-groups between the low CM group and the high CM group havethe same sequencing, wherein the last sub-group within the low CM groupand the first sub-group within the high CM group are adjacent with eachother while the first sub-group within the low CM group and the lastsub-group within the high CM group are adjacent with each other; whereinthe CMs of the ZC sequence within the low CM group are not larger thanthe CM of QPSK; and the CMs of the ZC sequence within the high CM groupare larger than the CM of QPSK; wherein the sequences are sequenced fromhigh to low or from low to high; wherein the logical index of thesequence within sub-group i is set smaller than the logical index of thesequences within sub-group i+1, wherein 1≦i≦S−1, the ith maximum cyclicshift threshold is Th_Ncs(i), and Th_Ncs(i)<Th_Ncs(i+1), wherein,1≦i≦S−2 and i is a positive integer; as for the low CM group, when1<i<S, the maximum value of the maximum cyclic shift supported by eachZC sequence within sub-group i is not less than Th_Ncs(i−1) and lessthan Th_Ncs(i); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is less than Th_Ncs(1);when i=S, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(S−1); orwhen 1<i<S, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is larger than Th_Ncs(i−1) and notlarger than Th_Ncs(i); when i=1, the maximum value of the maximum cyclicshift supported by each ZC sequence within sub-group i is not largerthan Th_Ncs(1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−1); and as for the high CM group, when 1<i<S, the maximum valueof the maximum cyclic shift supported by each ZC sequence withinsub-group i is not less than Th_Ncs(S−i) and less than Th_Ncs(S−i+1);when i=1, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(S−1); wheni=S, the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is less than Th_Ncs(1); or when 1<i<S, themaximum value of the maximum cyclic shift supported by each ZC sequencewithin sub-group i is larger than Th_Ncs(S−i) and not larger thanTh_Ncs(S−i+1); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not larger thanTh_Ncs(1); or wherein the logical index of the sequence within sub-groupi is set smaller than the logical index of the sequence within sub-groupi+1, wherein 1≦i≦S−1, the ith maximum cyclic shift threshold isTh_Ncs(i), and Th_Ncs(i)<Th_Ncs(i+1), wherein, 1≦i≦S−2 and i is apositive integer; as for the low CM group, when 1<i<S, the maximum valueof the maximum cyclic shift supported by each ZC sequence withinsub-group i is not less than Th_Ncs(i−1) and less than Th_Ncs(S−i+1);when i=1, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is not less than Th_Ncs(S−i); wheni=S, the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is less than Th_Ncs(1); or when 1<i<S, themaximum cyclic shift supported by each ZC sequence within sub-group i islarger than Th_Ncs(S−i) and not larger than Th_Ncs(S−i+1); when i=1, themaximum cyclic shift supported by each ZC sequence within sub-group ishould all be larger than Th_Ncs(S−1); when i=S, the maximum cyclicshift supported by each ZC sequence within sub-group i should all be notlarger than Th_Ncs(1); and as for the high CM group, when 1<i<S, themaximum value of the maximum cyclic shift supported by each ZC sequencewithin sub-group i is not less than Th_Ncs(i−1) and less than Th_Ncs(i);when i=1, the maximum value of the maximum cyclic shift supported byeach ZC sequence within sub-group i is less than Th_Ncs(1); when i=S,the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is not less than Th_Ncs(S−1); or when 1<i<S,the maximum value of the maximum cyclic shift supported by each ZCsequence within sub-group i is larger than Th_Ncs(i−1) and not largerthan Th_Ncs(i); when i=1, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is not larger thanTh_Ncs(1); when i=S, the maximum value of the maximum cyclic shiftsupported by each ZC sequence within sub-group i is larger thanTh_Ncs(S−1).
 5. The device according to claim 4, wherein the maximumcyclic shift is N_(CS)=min(du,N_(ZC)−2·du), wherein, du is the distancebetween the correlation peak alias and correlation peak, N_(ZC) is thelength of the ZC sequence.
 6. The device according to claim 5, whereinthe distance between the correlation peak alias and correlation peak is,${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\;\frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$ wherein u is the physical index of the ZCsequence, m is the minimum positive integer which makes$\frac{{m \cdot N_{ZC}} - 1}{u}$ a positive integer.